Self-orienting revolving fixture

ABSTRACT

A self-orienting revolving fixture for furniture which is of the type having parallel plates relatively rotatable about a central axis with antifriction means between the plates, a coil spring that has at least one convolution surrounding said axis with means on the plates to stress the spring by pulling circumferentially in opposite directions on the ends of the spring, there being a guide finger positioned radially inwardly from the spring and substantially in contact with the spring convolution in oriented position, the guide finger restricting bodily shifting movement and preventing differential stressing of the spring during relative rotation of the plates.

in United States Patent 51 am /M5 Miltos et all 51 Jan. 235, W72

54] SELF-OMENTING REVULVING 2,936,143 5/1960 Anderson ..248/145 FHXTMRE 3,096,964 7/1963 Fox ..248/4l7 1,680,828 8/1928 Walton .248/417 [72] Inventors: Aloysius J. Mikos, Skokie; Jerzy K. Ku-

baclti, Chicago, both of Ill. Primary Examiner-Edward C. Allen [73] Assigneez The g p y AttorneyHofgren, Wegner, Allen, S'tellman & McCord [22] Filed: May 21, 1969 [57] ABSTRACT [21] Appl. No.: 826,426 A self-orienting revolving fixture for furniture which is of the type having parallel plates relatively rotatable about a central axis with antifriction means between the plates, a coil spring [52] lU.S.Cl ..248/425, 248/417 that has at least one convolution surrounding said axis with MI. t means on the plates to stress the p i g circum Fleld ofSearch ferentially in pp directions on the ends of the p g, 16/142 182; 108/139 142; 49/386 there being a guide finger positioned radially inwardly from the spring and substantially in contact with the spring convolu- [56] References cued tion in oriented position, the guide finger restricting bodily UNTED STATES PATENTS shifting movement and preventing differential stressing of the spring during relative rotation of the plates. 2,634,454 4/1953 Altenburger ..l6/76 9 Claims, 6 Drawing Figures 26 z 5 27 12 i5 2g Y n Z? "l 12 22 3" 6 l 11/ liI ll l 18' I l I II. I

PMENTED Jmzsmz SHEET BF 3 W, M, v 7% L a SELF-ORIENTING REVOLVING FIXTURE BACKGROUND OF THE INVENTION The present invention is an improvement upon that of Fox US. Pat. No. 3,096,964. In that patent a self-orienting revolving fixture is provided with a coil spring that has several convolutions surrounding a pair of converging central bosses which are on the opposed plates of the revolving fixture, and the spring is disclosed as closely surrounding the bosses so that the bosses act to maintain the spring properly centered with respect to the axis of rotation of the fixture.

Extensive commercial experience with the fixture of US. Pat. No. 3,096,964 disclosed that pulling the spring into contact with the bosses caused it to be differentially stressed as the fixture was rotated from its oriented position, and this caused spring breakage with undesirably short fixture life. Further, as lubricant originally on the parts dried or wore off, the spring rubbing against the bosses caused undesirable noise. In addition, the binding of the spring against the bosses caused a condition in which only a small fraction of the total length of the spring was effective when the spring was in its fully stressed condition as seen in FIG. 4 of the patent drawings.

In order to eliminate the problems inherent in the structure of U.S. Pat. No. 3,096,964, the circumference of the spring was increased so as to space the spring convolutions radially outwardly from the bosses; but this produced a condition in which the spring slid off center as it was stressed, and this also resulted in inefficient use of the spring itself and the production of differential stresses causing spring breakage. Thus, the structural change which was expected to cure the defect in the US Pat. No. 3,096,964 structure turned out to be of little value.

SUMMARY OF THE INVENTION In accordance with the present invention, the spring circumference is made large enough that it is spaced a substantial distance outwardly from the central bosses on the plates, and a centering lug or guide finger on one of the plates is positioned radially inwardly from the spring and in contact with the spring convolutions so that as the spring is stressed the centering lug maintains concentricity of the spring with reference to the axis of rotation of the plates.

In particular, in the present construction one plate is provided with a pair of lugs which are circumferentially spaced from one another and serve to anchor the opposite ends of the spring when the plates are in their oriented position; and the other plate is provided with four lugs including two lugs for stressing the spring upon relative rotation of the plates that are positioned radially immediately adjacent the lugs of the twolug plate. The second plate also has the centering lug or guide finger which is angularly equidistant from the two stressing lugs, and a stop lug which is 180 from the centering lug and circumferentially aligned with the lugs on the two-lugplate so as to cooperate therewith in limiting relative rotation of the plates.

Although the fixture may be mounted on a piece of furniture with either of the two plates on the bottom, it is preferred to mount the two-lug plate on the bottom and the four-lug plate on top; and this is the arrangement illustrated in the drawings. When so arranged, the relatively fixed bottom plate anchors the two ends of the spring and, upon rotation of the top plate to stress the spring the centering lug moves with the spring with no relative motion between them. On the other hand, if the four-lug plate is on the bottom and the two-lug plate on top the centering lug is relatively fixed when the device is in use, and as the spring is stressed by pulling on one end or the other the spring convolutions must slide over the fixed centering lug.

DESCRIPTION OF THE DRAWINGS FIG. I is a plan view of a self-orienting revolving fixture em bodying the invention;

FIG. 2 is a central transverse sectional view taken substantially as indicated along the line 22 of FIG. 1;

FIG. 3 is a fragmentary sectional view taken substantially as indicated along the line 3-3 of FIG. 2 with the parts in their oriented position;

FIG. 4 is a view like FIG. 3 with the upper plate in the position of its maximum clockwise rotation;

FIG. 5 is a fragmentary sectional view of the top plate taken substantially as indicated along the line 5-5 of FIG. l; and

FIG. 6 is a fragmentary section taken substantially as indicated along the line 6-6 of FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings in greater detail, and referring first to FIGS. l and 2, a self-orienting revolving fixture includes a bottom plate, indicated generally at 10, provided with radially projecting ears 11 by means of which it may be secured to a furniture base B. A peripheral ball bearing raceway l2 and a central boss I3 which is axially apertured are also parts of the bottom plate I0, as are upstanding lugs 14 which are struck from the bottom plate between the raceway l2 and the boss 13, approximately apart.

A top plate, indicated generally at 15, has ears 116 by which it may be secured to the underside of a furniture member F which is to be rotatably mounted with respect to the base B, a ball bearing raceway which opposes the raceway I2, and a central boss 17 which protrudes toward the boss l3 and has an axial hole. The top plate has a pair of spring-stressing lugs I8, a stop lug I9, and a centering lug or guide finger 20 which is seen in FIG. 6 to be surrounded by a sleeve 21 of antifriction material such as Teflon.

Antifriction means in the form of ball bearings 22 are seated in he confronting raceways l2 and 12a so as to space the plates 10 and 15 apart and make them freely rotatable about their axis, and overlapping ball-positioning links 23 maintain the ball bearings 22 in spaced relationship about the raceways. A bolt 24 which impales the aligned axial holes in the bosses 13 and 17, and a nut 25 threaded onto the bolt, retain the plates 10 and 15 together for relative rotation.

In order that the top plate may be returned to the oriented position of FIG. 3 with respect to the bottom plate, a coil spring 26 which has at least one convolution 27 is positioned between the plates with a first end portion 27a engaging one of the upstanding lugs I4 and a second end portion 27b engaging the other of the upstanding lugs. Each of the depending spring-stressing lugs 18 also engages one of the end portions 27a or 27b of the spring 26. As best seen in FIGS. 3 and 4, the circumference of the spring 26 is great enough that it is spaced a substantial distance radially outwardly from the bosses I3 and I7, and the centering lug or guide finger 20 is positioned radially inwardly of the spring 26 with its antifriction sleeve 21 in direct contact with the spring in an area which is at equal angular distances from the spring-stressing lugs I8. When the upper plate I5 is rotated in either direction from the oriented position of FIG. 3 the centering lug 20 retains the spring 26 in its position of concentricity with respect to the axis of rotation of the plate defined by the bolt 24l.

As seen in FIG. 4, when the top plate reaches its position of maximum rotation in either direction the stop lug l9 strikes the end portion of the spring, in this case the portion 27b, and in order that there may be no objectionable noise when the stop strikes the spring rubber sleeve Zfli are mounted on the spring ends 27a and 27b.

The foregoing detailed description is given for clearness of understanding only and no unnecessary limitations should be understood therefrom, as modifications will be obvious to those skilled in the art.

We claim:

1. In a self-orienting revolving fixture of the type which has substantially flat, parallel plates including a lower plate for attachment to the top of a relatively fixed furniture base and an upper plate for attachment to the bottom of a furniture member. antifriction means between the plates spacing them apart and providing for free relative rotation about a central axis, coil spring means which has a plurality of spring coils substantially concentrically surrounding the central axis and spaced radially therefrom, said coils having opposite ends, a pair of circumferentially spaced upstanding lugs on the lower plate engaging both of the opposite spring ends when the plates are in said oriented position, a depending pulling lug on the upper plate which is radially adjacent one of the upstanding lugs in the oriented position and which engages one of said spring ends to stress the spring means as the plates are relatively rotated in one direction from said position, and stop means on said plates for limiting their relative rotation from said position, the improvement comprising:

guide finger means on one of the plates in a position which is between the upstanding lugs and on the same side of the pivot axis when the plates are oriented and radially inwardly of the spring, said guide finger means having a very small area of contact with the radially inward side of the spring coils in a location behind the pulling lug when the coils are stressed during relative rotation of the plates so as to restrict bodily shifting movement of the coils with respect to the pivot axis and prevent differential stressing of the spring.

2. The revolving fixture of claim 1 in which there is a single guide finger.

3, The revolving fixture of claim 1 in which the guide finger means and the stop means are both on the upper plate.

4. In a self-orienting revolving fixture of the type which has substantially flat, parallel plates including a lower plate for attachment to the top of a relatively fixed furniture base and an upper plate for attachment to the bottom of a furniture member, antifriction means between the plates spacing them apart and providing for free relative rotation about a central axis, coil spring means which has a plurality of spring coils substantially concentrically surrounding the central axis and spaced radially therefrom, said coils having opposite ends, a pair of circumferentially spaced upstanding lugs on the lower plate engaging both of the opposite spring ends when the plates are in said oriented position, a pair of depending pulling lugs on the upper plate each of which is radially adjacent one of the upstanding lugs in the oriented position so that each en gages one of said opposite spring ends to stress the spring means as the plates are relatively rotated one way or the other from said position, and stop means on said plates for limiting their relative rotation from said position, the improvement comprising:

guide finger means on one of the plates in a position which is between the upstanding lugs and on the same side of the pivot axis when the plates are oriented and radially inwardly of the spring, said guide finger means having a very small area of contact with the radially inward side of the spring coils in a location behind the pulling lug when the coils are stressed during relative rotation of the plates so as to restrict bodily shifting movement of the coils with respect to the pivot axis and prevent differential stressing of the spring.

5. The revolving fixture of claim 4 in which the lugs ofa pair are spaced circumferentially around the plate spaced from each other at an angle substantially less than there is a single guide finger positioned radially inwardly from the spring means on a radius of the plate which bisects said angle, and the stop means comprises a boss on one of the plates which is spaced 180 from the guide finger in a position to contact one of the lugs on the other plate to limit relative rotation of the plates.

6. The revolving fixture of claim 5 in which the guide finger and stop boss are both on the upper plate.

7. The revolving fixture of claim 4 in which there is a single guide finger and a single stop boss, both on the upper plate on a diameter of said plate which bisects the angle defined by the lu s.

a The revolving fixture of claim 4 in which the guide finger means is provided with antifriction means on the side toward the spring.

9. The revolving fixture of claim 4 in which the spring means comprises a single spring. 

1. In a self-orienting revolving fixture of the type which has substantially flat, parallel plates including a lower plate for attachment to the top of a relatively fixed furniture base and an upper plate for attachment to the bottom of a furniture member, antifriction means between the plates spacing them apart and providing for free relative rotation about a central axis, coil spring means which has a plurality of spring coils substantially concentrically surrounding the central axis and spaced radially therefrom, said coils having opposite ends, a pair of circumferentially spaced upstanding lugs on the lower plate engaging both of the opposite spring ends when the plates are in said oriented position, a depending pulling lug on the upper plate which is radially adjacent one of the upstanding lugs in the oriented position and which engages one of said spring ends to stress the spring means as the plates are relatively rotated in one direction from said position, and stop means on said plates for limiting their relative rotation from said position, the improvement comprising: guide finger means on one of the plates in a position which is between the upstanding lugs and on the same side of the pivot axis when the plates are oriented and radially inwardly of the spring, said guide finger means having a very small area of contact with the radially inward side of the spring coils in a location behind the pulling lug when the coils are stressed during relative rotation of the plates so as to restrict bodily shifting movement of the coils with respect to the pivot axis and prevent differential stressing of the spring.
 2. The revolving fixture of claim 1 in which there is a single guide finger.
 3. The revolving fixture of claim 1 in which the guide finger means and the stop means are both on the upper plate.
 4. In a self-orienting revolving fixture of the type which has substantially flat, parallel plates including a lower plate for attachment to the top of a relatively fixed furniture base and an upper plate for attachment to the bottom of a furniture member, antifriction means between the plates spacing them apart and providing for free relative rotation about a central axis, coil spring means which has a plurality of spring coils substantially concentrically surrounding the central axis and spaced radially therefrom, said coils having opposite ends, a pair of circumferentially spaced upstanding lugs on the lower plate engaging both of the opposite spring ends when the plates are in said oriented position, a pair of depending pulling lugs on the upper plate each of which is radially adjacent one of the upstanding lugs in the oriented position so that each engages one of said opposite spring ends to stress the spring means as the plates are relatively rotated one way or the other from said position, and stop means on said plates for limiting their relative rotation from sAid position, the improvement comprising: guide finger means on one of the plates in a position which is between the upstanding lugs and on the same side of the pivot axis when the plates are oriented and radially inwardly of the spring, said guide finger means having a very small area of contact with the radially inward side of the spring coils in a location behind the pulling lug when the coils are stressed during relative rotation of the plates so as to restrict bodily shifting movement of the coils with respect to the pivot axis and prevent differential stressing of the spring.
 5. The revolving fixture of claim 4 in which the lugs of a pair are spaced circumferentially around the plate spaced from each other at an angle substantially less than 180*, there is a single guide finger positioned radially inwardly from the spring means on a radius of the plate which bisects said angle, and the stop means comprises a boss on one of the plates which is spaced 180* from the guide finger in a position to contact one of the lugs on the other plate to limit relative rotation of the plates.
 6. The revolving fixture of claim 5 in which the guide finger and stop boss are both on the upper plate.
 7. The revolving fixture of claim 4 in which there is a single guide finger and a single stop boss, both on the upper plate on a diameter of said plate which bisects the angle defined by the lugs.
 8. The revolving fixture of claim 4 in which the guide finger means is provided with antifriction means on the side toward the spring.
 9. The revolving fixture of claim 4 in which the spring means comprises a single spring. 